Adaptive robust precision motion control of a flexible system with unmatched model uncertainties

Flexible systems which function under the influence of friction are very common in many applications such as flexible robot arms. The precision motion control of such systems is a difficult task because of the modelling difficulties involved in modelling friction and various flexible modes of the system. This paper presents the design of a nonlinear adaptive robust controller (ARC) to the precision motion control of a floating oscillator system under the influence of friction. This system consists of two masses moving on a track under the influence of friction and coupled by a spring. The floating oscillator acting under the influence of friction can be used to represent many applications such as hard disk drives and flexible robots where friction is present and the end effector position is to be controlled.